Mining operations can involve, inter alia, the use of machines arrayed, for example, along a long-wall mining face for cutting away the subterranean structure in a mine chamber or gallery to advance the chamber and allow recovery of the coal, rock or other material which is thus cut away. In typical long wall mining, for example, a plurality of cutters are arranged along the mining face and are advanced gradually or in steps, individually or in gaps, or in other controlled patterns to maintain the mining operation. The rock, coal or other mined material is carried away by conveyors and generally the machine or machines have facilities enabling them to be controlled by on-site operators.
Control of the operation is effected in various ways. For example, measuring devices can be provided for the resistance of the structure to attack by the mining machines, systems can be provided to monitor tool temperatures and various safety systems may be provided to prevent overloading of the machines. All of these systems, however, utilize very specialized parameters which may respond to some conditions and not others and cannot be used as generalized parameters for the effectiveness of the mining operation.